body {
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f5f5;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 40px auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

h1 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 30px;
}

.controls {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 30px;
}

.file-label {
    position: relative;
    display: inline-block;
    padding: 10px 20px;
    background-color: #3498db;
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.file-label:hover {
    background-color: #2980b9;
}

.file-label input[type="file"] {
    position: absolute;
    left: 0;
    top: 0;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

#generateButton {
    padding: 10px 20px;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#generateButton:hover {
    background-color: #219653;
}

#treeContainer {
    margin-top: 20px;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: #fafafa;
    min-height: 200px;
}

.tree {
    list-style-type: none;
    padding-left: 20px;
}

.tree li {
    margin: 8px 0;
    padding: 4px;
    border-left: 2px solid #ddd;
    transition: all 0.2s;
}

.tree li:hover {
    background-color: #f0f0f0;
    border-left-color: #3498db;
}
